Tag: "ancestral" at biology news

Scientists document complex genomic events leading to the birth of new genes

...mic rearrangements leading to the formation of the ancestral RGP locus. These events included a combination of duplication, inversion, partial deletion, and domain acquisition, and this was followed by a series of duplications that gave rise to each RGP family member. A total of eight RGP-family genes were ide...

New World founders small in number

...d models to incorporate changes in the size of the ancestral population and of each founder population through ...suggests that only about 70 individuals left their ancestral Asian population (estimated at about 9,000 individuals) to reach America 7,000 to 14,000 years ago. ...

Retrovirus struck ancestors of chimpanzees and gorillas millions of years ago, but did not affect ancestral humans

...ve to seven million years ago. During that period, ancestral humans were likely to be living in the same area o...n apes may have been susceptibile to the virus, or ancestral humans and Asian apes may have been resistant to it. Another possibility is that some early humans m...

Chimp genome reveals a retroviral invasion

...es the notion that an ancient infection invaded an ancestral primate lineage, since great apes (including humans) share a common ancestor with Old World monkeys. Eichler and colleagues found over 100 copies of PTERV1 in each African ape (chimp and gorilla) and Old World monkey (baboon and macaque) species. Th...

Scientists analyze chromosomes 2 and 4

...at human chromosome 2 arose from the fusion of two ancestral ape chromosomes, researchers supported by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), reported today. In a study published in the April 7 issue of the journal Nature, a multi-institution tea...

Map of life on Earth could be used on Mars

... into marine environments over time. "We have the ancestral Archeae ?it diverges into two major lineages, the Crenarchaeota and the Euryarchaeota, one which grows in marine environments, the other on continents, " Blank said. "They grow and diverge for perhaps a billion years, and then they start colonizing e...

Fungus-farming termites descend from an African rain forest Eve

...ed in African rain forest. Their reconstruction of ancestral habitats is based on the habitat of living species and analysis of DNA-based reconstructions of termite relationships. The rain forest origin of fungus-growing termites is remarkable, as extant species of fungus-growing termites are ecologically (in...

Big differences in duplicated DNA distinguish chimp and human genomes

...ly started out as a single copy of a segment in an ancestral species of both chimps and humans, and after the species split off from each other, that segment was duplicated many times in the human genome over millions of years. Most of the remaining one-third of duplication differences are due to deletion of s...

Human embryonic stem cells have the potential to develop into eggs and sperm in the laboratory

...les of primordial germ cells (PGCs), which are the ancestral cells that eventually form eggs and sperm (gametes). "Investigating the mechanisms of human primordial germ cell and gamete development is important for understanding the causes of infertility and the potential harmful effects of environmental chemic...

'Punctuated' evolution in the human genome

... that exhibit strong similarity to the euchromatic ancestral loci from which they were copied. According to Eic...identified segments of DNA that originated from 14 ancestral loci. These DNA segments, or "duplicons," ranged from 4-77 Kb in length and exhibited 94-99% sequenc...

Analysis of flower genes reveals the fate of an ancient gene duplication

...erent related species. Genes derived from a common ancestral gene region will still share similarities in neigh...owed that AG and PLE are not derived from the same ancestral gene, but that they instead represent two different products of a gene-duplication event that occurr...

When in danger humans are similar to a deer in the headlights

...detected is a defensive, protective reaction. This ancestral and automatic behavior allows the prey to stay unnoticed by a potential predator. A new study published in Psychophysiology finds that humans, like many other complex animals, freeze when encountering a threat. The mere picture of an injured or mutil...

Researchers create functioning artificial proteins using nature's rules

...s have today are the result of fine-tuning a basic ancestral template that we have now figured out." Proteins, which carry out the body's life functions, are composed of molecules called amino acids, which are strung together in long chains. These chains loop about each other, or fold, in a variety of ways. T...

From a Few Wild Ancestors, a Citrus Cornucopia

...n the world and that the rest are hybrids of these ancestral forms. The research also supports the generally he...ines,?says Krueger, “often at the expense of wild, ancestral types.?/p> This doesn’t mean that new citrus types won’t be developed through conventional breed...

DNA traces evolution of extinct sabertooths and the American cheetah-like cat

...e New World may have given rise to Miracinonyx and ancestral Puma a few million years ago, around the time that the North American prairie is thought to have undergone expansion. ...

Cornell finds natural selection in humans

...o identify which form of the gene was the original ancestral form and which was the derived or new type. The original goal of the project was to identify novel amino acid variants that could then be tested for association with human disease in subsequent studies. The Cornell researchers became involved at the ...

Ancient anthropoid origins discovered in Africa

...e fossils in Asia do not constitute evidence of an ancestral crown anthropoid lineage there." According to Seiffert, the latest findings help fill in the gap between later anthropoids and the oldest undisputed anthropoid, called Algeripithecus, found in Algeria, which lived around 45 million years ago. That s...

New technique multiplies life span in simple organisms

...ncers." Homologs are genes descended from a common ancestral DNA sequence. Joining with researchers at the USC Norris Comprehensive Cancer Center, Longo is studying the feasibility of reducing or preventing the age-dependent DNA mutations that cause cancer. Longo and his collaborators began studying SIR2 in ...

Did feathered dinosaurs exist?

...ported finding all stages of feather evolution and ancestral birds, even though the deposits are at least 25 million years younger than those containing the earliest known bird Archaeopteryx. Researchers, led by Alan Feduccia of the University of North Carolina at Chapel Hill, considered the new findings in ...

Missing fossil link 'Dallasaurus' found

...ain land-capable limbs, they were thought to be an ancestral group separate from the later fin-bearing forms. Dallasaurus represents a clear link to one lineage of the later forms and the first time researchers can clearly show mosasaurs evolved fins from limbs within the different lineages of mosasaurs. With...

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